shill: Hook up Create/Pop/PushProfile to dbus

Have the manager profile methods written so far link up
with the RPC Manager Adaptor code.

BUG=chromium-os:24326
TEST=Unit tests for regression.  Also used flimflam's Python
create-profile/push-profile as well as logging out/in on a
shill instance running with --use-flimflam-profiles

Change-Id: I69f3a94e6cb3acda5ae37ec005b2345566e5e700
Reviewed-on: https://gerrit.chromium.org/gerrit/13070
Commit-Ready: Paul Stewart <pstew@chromium.org>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
diff --git a/profile.cc b/profile.cc
index 5a2ff3e..4390d23 100644
--- a/profile.cc
+++ b/profile.cc
@@ -105,6 +105,10 @@
 }
 
 string Profile::GetRpcIdentifier() {
+  if (!adaptor_.get()) {
+    // NB: This condition happens in unit tests.
+    return string();
+  }
   return adaptor_->GetRpcIdentifier();
 }